Proceedings of the second international meeting on endemic mycoses of the Americas (IMEMA) and first international symposium on implantation mycoses (ISIM).

The second international meeting on endemic mycoses of the Americas (IMEMA) and the first international symposium on implantation mycoses (ISIM) took place in Santiago del Estero, Argentina, on September 25-27, 2023. The conference provided a platform for researchers, clinicians, and experts to discuss the latest developments in the field of endemic and implantation mycoses. Topics included epidemiology, diagnostic advances, treatment strategies, and the impact of environmental factors on the spread of these fungal diseases. IMEMA and ISIM contributed to the regional discourse on the mycoses, emphasizing the importance of international cooperation in addressing these public health challenges.

IMEMA/ISIM, held in Santiago del Estero, Argentina, convened experts to discuss endemic and implantation mycoses, covering topics such as epidemiology, diagnostics, treatment, and advocacy. The event highlighted ongoing efforts in combating these diseases.

Sonication protocols and their contributions to the microbiological diagnosis of implant-associated infections: a review of the current scenario.

Addressing the existing problem in the microbiological diagnosis of infections associated with implants and the current debate about the real power of precision of sonicated fluid culture (SFC), the objective of this review is to describe the methodology and analyze and compare the results obtained in current studies on the subject. Furthermore, the present study also discusses and suggests the best parameters for performing sonication. A search was carried out for recent studies in the literature (2019-2023) that addressed this research topic. As a result, different sonication protocols were adopted in the studies analyzed, as expected, and consequently, there was significant variability between the results obtained regarding the sensitivity and specificity of the technique in relation to the traditional culture method (periprosthetic tissue culture - PTC). Coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus were identified as the main etiological agents by SFC and PTC, with SFC being important for the identification of pathogens of low virulence that are difficult to detect. Compared to chemical biofilm displacement methods, EDTA and DTT, SFC also produced variable results. In this context, this review provided an overview of the most current scenarios on the topic and theoretical support to improve sonication performance, especially with regard to sensitivity and specificity, by scoring the best parameters from various aspects, including sample collection, storage conditions, cultivation methods, microorganism identification techniques (both phenotypic and molecular) and the cutoff point for colony forming unit (CFU) counts. This study demonstrated the need for standardization of the technique and provided a theoretical basis for a sonication protocol that aims to achieve the highest levels of sensitivity and specificity for the reliable microbiological diagnosis of infections associated with implants and prosthetic devices, such as prosthetic joint infections (PJIs). However, practical application and additional complementary studies are still needed.

Surveillance of osteoarticular infections caused by Staphylococcus aureus in a paediatric hospital in Mexico City.

Staphylococcus aureus is the main aetiologic agent of osteoarticular infections (OAIs) in paediatric patients. The aim of this prospective unicenter study was to describe the phenotypic and genotypic characteristics of S. aureus isolates obtained from OAIs in paediatric patients admitted to tertiary care hospital. Through a surveillance program called OsteoCode, a multidisciplinary team was created and we identified 27 patients with OAIs caused by S. aureus from 2019 to 2021. The susceptibility profile, virulence factors, biofilm formation, pulsed-field gel electrophoresis (PFGE), clonal complex (CC) and sequence type (ST) were determined. In addition, the clinical characteristics and evolution of the patients presented six months after the diagnosis of OAIs were described. Ninety-two percent of the isolates were methicillin-sensitive S. aureus (MSSA). In methicillin-resistant S. aureus (MRSA), SCCmec-II and SCCmec-V were detected. The pvl gene was only observed in MSSA (18.5%) and was associated with highest fever (p=0.015), multiple localization (p=0.017), and soft tissue sites of infection beyond the bone (pyomyositis, pulmonary abscess) (p=0.017). Biofilm formation was detected in 55.6% of isolates. The most common CC were CC5 and CC30 which represent the most common linages for bone and joint infections worldwide. The isolates were distributed in different STs, and ST672 was predominant. MRSA were associated with a longer duration of intravenous treatment and a prolonged hospital stay (p=0.023). Recurrent infection occurred in five children and orthopaedic complications in 33.3% of patients. This is the first study that reflects the epidemiology of S. aureus in OAIs in paediatric patients in Mexico; a clear predominance of MSSA distributed in different STs was observed. Our findings highlight that a multidisciplinary team is required for the diagnosis and treatment of OAIs.

Prosthetic joint infection due to Candida species: Case series and review of literature.

INTRODUCTION: The increase in the number of patients with prosthetic joints will entail a rise in the absolute number of infections associated with these procedures. Although less frequent, infections by Candida species are also expected to increase, and the clinical and surgical management of these cases is based on case reports and opinion of specialists. The objective of the present study was to review the available literature and describe the cases of prosthetic joint infection caused by Candida species in patients of the Institute of Orthopedics and Trauma of the University of São Paulo Faculty of Medicine Clinics Hospital (IOT-HCFMUSP) between 2007 and 2014. PATIENT CONCERNS: Eleven patients were diagnosed with prosthetic joint infection due to Candida with mean age of 65 years. The most frequent comorbidities were heart disease and diabetes mellitus, and the main personal antecedent was previous bacterial infection in the prosthetic joint. At least one risk factor for fungal infection was present in 73% of the patients. There was no difference between the prevalence of infections caused by Candida albicans and non-albicans Candida species, and there was bacterial co-infection in 55% of the cases. DIAGNOSIS: For building up the case series, patients with cultures of bone and joint specimens that were positive for Candida species and had a clinical diagnosis of prosthetic joint infection were included in the case series. INTERVENTIONS: Surgical debridement with removal of the prosthesis was the most frequently used surgical approach (45%). All patients were treated with monotherapy, and the most frequently used antifungal agent was fluconazole. The total duration of antifungal therapy was 6 months in 73% of the cases. OUTCOMES: After the initial management, 73% of the patients achieved clinical remission. CONCLUSION: The most indicated initial management was debridement with removal of the prosthesis, and the most used treatment regimen was fluconazole monotherapy. The most prevalent treatment duration was 6 months. The initial management led to a favorable outcome in 73% of the cases. DESCRIPTORS: Prosthetic joint infection, Candida, treatment, and diagnosis.

Propionibacterium acnes Endophthalmitis Following Baerveldt Glaucoma Device Implantation.

PURPOSE: The purpose of this study was to report a case of Propionibacterium acnes endophthalmitis in a patient with a Baerveldt glaucoma implant. PATIENTS AND METHODS: An 8-year-old boy presented with left eye pain, extreme photophobia, and acute anterior uveitis >6 months after Baerveldt glaucoma implantation. A diagnosis of P. acnes endophthalmitis was made after a positive culture of the explanted Baerveldt device. RESULTS: Initially, the patient was treated with intravitreal vancomycin and ceftazidime which led to mild early clinical improvement followed by deterioration of findings with recurrence of fibrin at the Baerveldt tube ostium within the anterior chamber. Repeat intravitreal injections were given to include antifungal coverage, along with intracameral moxifloxacin and subconjunctival vancomycin around the Baerveldt reservoir. Symptoms and findings again recurred, ultimately leading to the decision for complete removal of the glaucoma implant along with irrigation of the scleral bed with moxifloxacin. P. acnes was cultured from the extracted implant. The endophthalmitis resolved completely after implant removal. CONCLUSIONS: Despite the introduction of antibiotics into the intravitreal, intracameral, and subconjunctival space surrounding the Baerveldt implant, infection persisted until complete explantation of the device. Early explantation should be considered in glaucoma drainage device endophthamitis secondary to P. acnes.

Genotypic and phenotypic changes of Staphylococcus epidermidis during relapse episodes in prosthetic joint infections.

Staphylococcus epidermidis is a coagulase-negative bacterium capable of causing recurrent relapses in prosthetic joint infection (PJI). The aim of this study was to determine if Staphylococcus epidermidis isolates from patients with recurrent relapses of prosthetic joint infection (PJI) changed genotypically (pulsed-field gel electrophoresis (PFGE) pattern analysis and genes involved in biofilm formation) and phenotypically (antimicrobial resistance, biofilm formation) during the different episodes. Four patients with PJI recurrent relapses were evaluated clinically and microbiologically. Genotypic and phenotypic characteristics of 31 S. epidermidis isolates were determined. In all cases, PJI was treated with antimicrobial therapy and resection of the prosthesis without reimplantation. Months later, all patients had a relapse episode and treated with rifampin plus vancomycin and surgical debridement. Changes in the antibiotics resistance profile in isolates from patients 1 and 2 were observed in the two episodes. Patient 1 had four clones A, B, C, and D that were distributed differentially in the two episodes. Similarly, patients 2 and 3 had two clones and subclones (E-E1 and F-F1, respectively), and patient 4 had only the clone G in both episodes. The clone F formed small-colony variants (SCVs). High level of biofilm formation was found in all clones, except for clones D and G. Clones/subclones showed a genotypic variation in icaA, sdrF, bap, sesI, and embp genes. The principal coordinate analysis showed that all clones/subclones were different. These results showed that the initial infective clone of S. epidermidis from PJI, changed genotypically and phenotypically after a second relapse as a response to the treatment.

Staphylococcus aureus Small Colony Variants (SCVs): News From a Chronic Prosthetic Joint Infection.

Small colony variants (SCV) of Staphylococcus aureus have been reported as implicated in chronic infections. Here, we investigated the genomic and transcriptomic changes involved in the evolution from a wild-type to a SCV from in a patient with prosthetic joint infection relapse. The SCV presented a stable phenotype with no classical auxotrophy and the emergence of rifampicin resistance. Whole Genome Sequencing (WGS) analysis showed only the loss of a 42.5 kb phage and 3 deletions, among which one targeting the rpoB gene, known to be the target of rifampicin and to be associated to SCV formation in the context of a constitutively active stringent response. Transcriptomic analysis highlighted a specific signature in the SCV strain including a complex, multi-level strategy of survival and adaptation to chronicity within the host including a protection from the inflammatory response, an evasion of the immune response, a constitutively activated stringent response and a scavenging of iron sources.

Non-biofilm-forming commensal Staphylococcus epidermidis isolates produce biofilm in the presence of trypsin.

Epidemiological studies comparing clinical and commensal Staphylococcus epidermidis isolates suggest that biofilm formation is a discriminant biomarker. A study showed that four non-biofilm-forming clinical S. epidermidis isolates could form an induced biofilm by trypsin treatment, suggesting that S. epidermidis can form biofilms in a protease-independent way and in a trypsin-induced way. In this study, the trypsin capacity to induce biofilm formation was evaluated in non-biofilm-forming S. epidermidis isolates (n = 133) in order to support this mechanism and to establish the importance of total biofilms (meaning the sum of protease-independent biofilm and trypsin-induced biofilm). Staphylococcus epidermidis isolates from ocular infections (OI; n = 24), prosthetic joint infections (PJI; n = 64), and healthy skin (HS-1; n = 100) were screened for protease-independent biofilm formation according to Christensen's method. The result was that there are significant differences (p < .0001) between clinical (43.2%) and commensal (17%) protease-independent biofilm producers. Meanwhile, non-biofilm-forming isolates were treated with trypsin, and biofilm formation was evaluated by the same method. The number of commensal trypsin-induced biofilm producers significantly increased from 17% to 79%. In contrast, clinical isolates increased from 43.2% to 72.7%. The comparison between clinical and commensal total biofilm yielded no significant differences (p = .392). A similar result was found when different isolation sources were compared (OI vs. HS-1 and PJI vs. HS-1). The genotype icaA- /aap+ was associated with the trypsin-induced biofilm phenotype; however, no correlation was observed between aap mRNA expression and the level of trypsin-induced biofilm phenotype. Studying another group of commensal S. epidermidis non-biofilm-forming isolates (HS-2; n = 139) from different body sites, it was found that 70 isolates (60.3%) formed trypsin-induced biofilms. In conclusion, trypsin is capable of inducing biofilm production in non-biofilm-forming commensal S. epidermidis isolates with the icaA- /aap+ genotype, and there is no significant difference in total biofilms when comparing clinical and commensal isolates, suggesting that total biofilms are not a discriminant biomarker.

Prevalence and virulence factors of coagulase negative Staphylococcus causative of prosthetic joint infections in an orthopedic hospital of Mexico.

Objective: To determine the prevalence and virulence factors of coagulase-negative Staphylococci (CNS) in prosthetic joint infections (PJI). Method: CNS were isolated of 66 hip and knee PJI from Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, México City. Antimicrobial susceptibility and biofilm formation in CNS were determined; icaADBC, aap, bap and embp genes were determined by PCR. Results: Staphylococcus and Staphylococcus hominis were the most prevalent with 82 y 80% respectively. Staphylococcus lugdunensis, Staphylococcus haemolyticus, Staphylococcus capitis, Staphylococcus caprae, Staphylococcus sciuri and Staphylococcus lentus were less frequent. The majority of isolates were resistant to ß-lactam antibiotics, fluoroquinolone, and erythromycin. 41% of CNS were biofilm former and 59% were non-biofilm former (p = 0.0551). Biofilm former Staphylococcus epidermidis showed a high presence of icaADBC, aap and embp operons compared to the non-biofilm former isolates (p < 0.05). In contrast, non-S. epidermidis CNS had only the aap gen. Conclusion: S. haemolyticus, S. sciuri and S. lentus are new isolates of PJI not previously reported with virulence factors similar to CNS isolates.

Objetivo: Estudiar la prevalencia y los factores de virulencia de Staphylococcus coagulasa negativos (SCN) de infecciones de prótesis articular (IPA). Método: Los SCN se aislaron de 66 pacientes con IPA de cadera y rodilla procedentes del Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, de Ciudad de México. Se determinaron la sensibilidad antimicrobiana y la producción de biopelículas de los SCN. Los genes icaADBC, aap, bap y embp fueron detectados por reacción en cadena de la polimerasa en SCN. Resultados: La IPA de cadera fue el 80%. Se aislaron en alta proporción S. epidermidis (82%) y S. hominis (80%), y en baja frecuencia S. lugdunensis, S. haemolyticus, S. capitis, S. caprae, S. sciuri y S. lentus. La mayoría de los aislamientos fueron resistentes a los betalactámicos, las fluoroquinolonas y la eritromicina. La producción de biopelículas se determinó en el 41% de los SCN y el 59% fueron no productores de biopelículas (p = 0.0551). S. epidermidis productores de biopelículas tuvieron mayor presencia del operón icaADBC, aap y embp que los aislamientos no productores de biopelícula (p < 0.05). Los SCN no S. epidermidis presentaron únicamente el gen aap. Conclusiones: S. haemolyticus, S. sciuri y S. lentus son aislamientos nuevos de IPA no reportados que poseen factores de virulencia, igual que las otras especies de SCN aisladas.

What Are the Benefits and Risks Associated With the Use of Vancomycin Powder in the Wound During Total Ankle Arthroplasty (TAA) or Other Foot and Ankle Procedures?

RECOMMENDATION: Though one study supporting topically applied vancomycin has shown it to reduce the rate of deep infection in diabetic patients undergoing foot and ankle surgery, there is insufficient evidence to show benefits or to show any risks associated with the use of vancomycin powder during total ankle arthroplasty (TAA) or other foot and ankle procedures in a general population. LEVEL OF EVIDENCE: Consensus. DELEGATE VOTE: Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

What Prophylactic Antibiotic (Type, Dose and Route of Administration) Should Be Administered Perioperatively for Patients Undergoing Total Ankle Arthroplasty (TAA)?

RECOMMENDATION: The administration of prophylactic antibiotics before total ankle arthroplasty (TAA) potentially reduces the incidence of surgical site infection (SSI) and/or periprosthetic joint infection (PJI). Weight-based (of at least 2 g) cefazolin administered intravenously within 60 minutes before the procedure can be an adequate choice for antibiotic prophylaxis. If the patient has a beta-lactam anaphylaxis, we recommend an appropriate alternative antibiotic effective against Staphylococcus. It is unclear whether prophylaxis should be given as a single dose or as multiple doses. LEVEL OF EVIDENCE: Strong. DELEGATE VOTE: Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Do Culture Negative Periprosthetic Joint Infections Remain Culture Negative?

BACKGROUND: Diagnosis and treatment of culture negative total knee arthroplasty (TKA) periprosthetic joint infection (PJI) is challenging. There is debate over whether culture negative PJI confers increased risk of failure and which organisms are responsible. It is also unclear as to what factors predict conversion from culture negative to culture positivity. To address these issues, we performed an observational study to detect factors associated with transition from culture negative to culture positive TKA PJI in those patients that failed irrigation and debridement (I&D), determine the incidence of this transition, and identify those organisms that were associated with treatment failure. METHODS: A multicenter observational cohort study was performed on patients with TKA PJI as defined by Musculoskeletal Infection Society criteria without cultured organisms and treated with I&D. Primary outcome was failure defined as any subsequent surgical procedure. Secondary outcome included cultured organism within 2 years of initial I&D. RESULTS: Two hundred sixteen TKA I&D procedures were performed for PJI, and 36 met inclusion criteria. The observed treatment failure rate for culture negative PJI treated with I&D was 41.67%. Of those culture negative I&Ds that failed, 53.33% became culture positive after failure. Of those that converted to culture positive, 62.5% were Staphylococcus species. The odds ratio associated with becoming culture positive following culture negative treatment failure in the setting of antibiotic administration prior to the initial I&D procedure was 0.69 (95% confidence interval 0.14-3.47, P = .65). CONCLUSION: Many cases of culture negative TKA PJI treated with I&D eventually fail and become culture positive. Staphylococci are common organisms identified after culture negative PJI.

sesA, sesB, sesC, sesD, sesE, sesG, sesH, and embp genes are genetic markers that differentiate commensal isolates of Staphylococcus epidermidis from isolates that cause prosthetic joint infection.

OBJECTIVES: Staphylococcus epidermidis can cause prosthetic joint infections. Strategies to differentiate between healthy skin and prosthetic joint infections isolates are relatively ineffective, which makes necessary to search for new differential biomarkers. Staphylococcus epidermidis has eleven surface proteins, denoted as Ses proteins. In this work, ses genes are used as biomarkers to differentiate between prosthetic joint infections and healthy skin isolates. METHODS: All prosthetic joint infections (n = 51) and healthy skin (n = 51) isolates were genotyped by pulsed-field gel electrophoresis. icaA, embp, sesA-I, and sdrF genes were determined by PCR. The phenotypic data included biofilm production and antibiotic resistance. RESULTS: 10 pulsed-field gel electrophoresis profiles were identified: four profiles were exclusive of prosthetic joint infections isolates, three profiles presented a higher proportion in prosthetic joint infections isolates and three profiles presented a higher proportion in healthy skin isolates. sesA, sesB, sesC, sesD, sesE, sesG, and sesH genes were more prevalent in healthy skin isolates than in prosthetic joint infections isolates (p < .05). Prosthetic joint infections isolates were more resistant to oxacillin (78%), ciprofloxacin (60%), levofloxacin (60%), and moxifloxacin (57%). The principal coordinate analysis and a discriminant analysis found that prosthetic joint infections isolates had as discriminant biomarker the biofilm formation, the icaA gene, oxacillin, ciprofloxacin, levofloxacin, moxifloxacin, and gentamicin resistance. In contrast, the healthy skin isolates had as discriminant biomarkers the embp, sesA, sesB, sesC, sesD, sesE, sesG, and sesH genes. CONCLUSIONS: These data suggest that ses genes can be considered biomarkers to differentiate between S. epidermidis commensal and prosthetic joint infections clinical.

Ventriculitis associated with extraventricular drainage: etiology, diagnosis and treatment focused on neurocritic care units.

Ventriculitis after extraventricular drainage is a very important neurosurgical complication in neurocritical care units. It is necessary to make an early diagnosis, given that the morbidity and mortality secondary to it can be variable, and complicate the evolution of neurocritical patients. Despite this, ventriculostomy continues to be an important pillar in monitoring and treatment. Given the urgency of ventriculitis associated with multiresistant germs, new antimicrobial drugs have emerged as part of the treatment, as intraventricular routes have been proposed within the new investigations. However, the foregoing does not yet have sufficient bases to be able to support it. The present review was carried out with the aim of contributing to an early diagnosis and treatment of ventriculitis associated with extra ventricular drainage in neurocritical patients, and in this way to contribute to improve survival and prevent fatal outcomes in these patients.

La ventriculitis posterior a un drenaje extraventicular constituye una complicación neuroquirúrgica muy importante en las unidades de cuidados neurocríticos. Se hace necesario realizar un diagnóstico precoz, dado que la morbimortalidad secundaria a esta puede ser variable y complicar la evolución de los pacientes neurocríticos. A pesar de esto, la ventriculostomía continúa siendo un pilar importante en el monitoreo y el tratamiento. Ante la urgencia de ventriculitis asociadas a gérmenes multirresistentes han surgido nuevos fármacos antimicrobianos como parte del tratamiento, al igual que se han propuesto vías intraventriculares dentro de las nuevas investigaciones. Sin embargo, lo anterior aún no tiene bases suficientes para poder ­sustentarlo. La presente revisión se realizó con el objetivo de contribuir a un diagnóstico precoz y al tratamiento de la ventriculitis asociada a drenaje extraventricular en pacientes neurocríticos, y de esta forma poder mejorar la sobrevida y prevenir desenlaces fatales en estos pacientes.

Lateral femoral bypass for prosthetic arterial graft infections in the groin.

OBJECTIVE: Prosthetic arterial graft infections (PAGIs) in the groin pose significant challenges in terms of revascularization options and risk of limb loss as well as associated morbidities. Although obturator canal bypass (OCB) has been suggested for revascularization of the extremity in these cases, moderate success rates and technical challenges have limited widespread use. Our study analyzed lateral femoral bypass (LFB) as an alternative approach for the treatment of groin PAGIs. METHODS: This is a retrospective review of a prospectively maintained database of patients who underwent LFB for groin PAGIs at a single center from 2000 to 2017. Patients' data including demographics, comorbidities, perioperative complications, graft patency, and need for reintervention were used. Patients were observed after LFB with duplex ultrasound surveillance in an accredited noninvasive vascular laboratory every 3 months during the first year, followed by every 6 months for the second year and yearly thereafter. After isolation of the infected wound with sterile dressings, remote proximal and distal arterial exposure incisions were made. LFBs were tunneled under the inguinal ligament and lateral to the infected wound from an uninvolved inflow artery or bypass graft to an uninvolved outflow vessel. RESULTS: A total of 19 LFBs were performed in 16 patients (mean age, 69 ± 12.6 years). Three LFBs were performed urgently for acute bleeding. Choice of conduit included 6 (31.6%) autogenous vein grafts, 10 (52.6%) cadaveric grafts, 2 (10.5%) rifampin-soaked Dacron grafts, and 1 (5.3%) polytetrafluoroethylene graft. Average follow-up was 33 months (range, 0-103 months). Major adverse events occurring within 30 days of the operation included one (5.3%) death and one (5.3%) graft excision for pseudoaneurysm. Primary patency and primary assisted patency at 12 and 24 months were 73% and 83%, respectively. One patient required an amputation 17 months after surgery after failure of repeated revascularization attempts. Overall limb salvage was 93.8% during this follow-up period. CONCLUSIONS: In this series, LFB for management of groin PAGIs demonstrated higher patency and limb salvage rates compared with previous reports of OCB. Diligent postoperative duplex ultrasound surveillance is critical to the achievement of limb salvage and maintenance of graft patency. These results suggest that LFB, which is technically less complex than OCB, should be considered the first choice for revascularization in select cases of PAGIs involving the groin.

Preoperative Anemia Is Associated With Failure of Open Debridement Polyethylene Exchange in Acute and Acute Hematogenous Prosthetic Joint Infection.

BACKGROUND: Acute and acute hematogenous prosthetic joint infections (PJIs) are often treated with open debridement and polyethylene exchange (ODPE) in an effort to save the prosthesis, decrease morbidity, and reduce costs. However, failure of ODPE may compromise a subsequent 2-stage treatment. The purpose of this study is to identify patient factors that impact the success of ODPE for acute and acute hematogenous PJIs. METHODS: A retrospective review examined comorbidities, preoperative laboratory values, and patient history for patients with successful and failed ODPE treatment for acute perioperative or acute hematogenous periprosthetic hip or knee joint infections. Successful treatment was defined as retaining a well-fixed implant without the need for additional surgery for a minimum of 6-month follow-up with or without lifelong oral maintenance antibiotics. RESULTS: Fifty-three of 72 patients (73.6%) underwent successful ODPE. Of the 19 failures, 14 completed 2-stage revision with one subsequent known failure for recurrent infection. Patients with a Staphylococcus aureus infection were more likely to fail ODPE (48.3% vs 11.6%, P = .0012, odds ratio 7.1, 95% confidence interval 2.3-25.3). Patients with a preoperative hematocrit ≤32.1 were also more likely to fail ODPE (55% vs 16%, P = .0013, odds ratio 6.7, 95% confidence interval 2.2-22.4). When neither risk factor was present, 97.1% of PJIs were successfully treated with ODPE. CONCLUSION: S aureus infection and preoperative hematocrit ≤32.1 are independent risk factors for ODPE failure. ODPE is a safe alternative to 2-stage revision in patients without preoperative anemia and without S aureus infection. Two-thirds of patients with a failed ODPE were successfully treated with a 2-stage reimplantation.

Influence of biomaterials on scintigraphic diagnosis of periprosthetic infections. Ceftizoxime-99m technetium model.

PURPOSE: To compare the influence of two metallic implants in the diagnosis of periprosthetic infection using 99m technetium-labeled ceftizoxime. METHODS: Twenty rats were randomly divided into four groups, which received sterile and contaminated titanium and stainless steel implants. After 3 weeks, scintilographic images were obtained using a gamma chamber. Radioactivity counts were obtained for the region of interest (ROI) on the operated and non-operated paws. RESULTS: Groups A, B, and C showed homogenous distribution of the radiopharmaceutical. Hyper uptake was observed in the operated paw from group D. The ROI target count was higher in the two groups with stainless steel implants. Among the control groups, the count was higher in the stainless steel group. Furthermore, among the contaminated groups, the uptake was higher in the stainless steel group, with a significant difference. The target: non-target ratio was significantly lower in the control and contaminated groups with both titanium and stainless steel, but the comparison between control groups and contaminated groups was only significant in the former. The cpm/g observed after a decay of 48h showed statistically significant differences between groups. CONCLUSION: Different biomaterials used in implants have an influence on the results of scintigraphy with 99mTc-CFT.

Influence of biomaterials on scintigraphic diagnosis of periprosthetic infections. Ceftizoxime-99m technetium model

Abstract Purpose: To compare the influence of two metallic implants in the diagnosis of periprosthetic infection using 99m technetium-labeled ceftizoxime. Methods: Twenty rats were randomly divided into four groups, which received sterile and contaminated titanium and stainless steel implants. After 3 weeks, scintilographic images were obtained using a gamma chamber. Radioactivity counts were obtained for the region of interest (ROI) on the operated and non-operated paws. Results: Groups A, B, and C showed homogenous distribution of the radiopharmaceutical. Hyper uptake was observed in the operated paw from group D. The ROI target count was higher in the two groups with stainless steel implants. Among the control groups, the count was higher in the stainless steel group. Furthermore, among the contaminated groups, the uptake was higher in the stainless steel group, with a significant difference. The target: non-target ratio was significantly lower in the control and contaminated groups with both titanium and stainless steel, but the comparison between control groups and contaminated groups was only significant in the former. The cpm/g observed after a decay of 48h showed statistically significant differences between groups. Conclusion: Different biomaterials used in implants have an influence on the results of scintigraphy with 99mTc-CFT.

Early prosthetic valve endocarditis caused by Corynebacterium amycolatum: the first case reported in Brazil.

Non-diphtheriae Corynebacterium species are usually considered as contaminants of clinical specimens due to their widely environmental distribution and colonization of the human skin and mucous membranes. However, these bacteria have been increasingly recognized as agents of life-threatening infections mainly in individuals in immunosuppressive conditions. These organisms have vast variation in morphology and biochemical reaction, characteristics that make the correct identification of Corynebacterium at the species level extremely difficult using conventional phenotypic methods. The precise identification of C. amycolatum requires approaches rarely available in conventional clinical microbiology laboratories, such as API Coryne system, 16s rRNA and rpoB gene sequencing. In this setting, MALDI-TOF, a quick, accurate, and relatively unexpansive molecular technique, arises as a cost-effective alternative for characterizing these agents. Here, a rare and lethal case of endocarditis caused by C. amycolatum is presented. This is the first case of infective endocarditis due to C. amycolatum reported in Brazil.